New paleo paper shows solar impact on past temperatures

There are multiple factors that affect both regional and global temperatures, but the most important source of long-term temperature change is solar activity. Using data from the Norwegian Sea and multiple solar proxies, the peer-reviewed research by Sejrup et al. confirms a robust and synchronous correlation between solar activity and temperatures.

Note: This research was conducted and completed without the use of magical “hockey stick” science and statistics, perfected by Penn State University personnel.

“…worked with two sediment cores they extracted from the seabed of the eastern Norwegian Sea, developing a 1000-year proxy temperature record “based on measurements of δ18O in Neogloboquadrina pachyderma, a planktonic foraminifer that calcifies at relatively shallow depths within the Atlantic waters of the eastern Norwegian Sea during late summer,” which they compared with the temporal histories of various proxies of concomitant solar activity…..This work revealed, as the seven scientists describe it, that “the lowest isotope values (highest temperatures) of the last millennium are seen ~1100-1300 A.D., during the Medieval Climate Anomaly, and again after ~1950 A.D.” In between these two warm intervals, of course, were the colder temperatures of the Little Ice Age, when oscillatory thermal minima occurred at the times of the Dalton, Maunder, Sporer and Wolf solar minima, such that the δ18O proxy record of near-surface water temperature was found to be “robustly and near-synchronously correlated with various proxies of solar variability spanning the last millennium,” with decade- to century-scale temperature variability of 1 to 2°C magnitude.” [Sejrup, H. P., S. J. Lehman, H. Haflidason, D. Noone, R. Muscheler, I. M. Berstad, and J. T. Andrews 2010: J. Geophys. Res]

I wonder if they accounted for the tendency of cosmic rays to form oxygen isotopes? Sunspot minima are cosmic-ray maxima, so it would seem logical that more isotopes would be formed during sunspot minima. This would happen independent of the Svensmark temperature effects of cosmic rays.

Their use of the Group Sunspot Number in their figure 2d [see http://www.leif.org/EOS/2010JC006264.pdf ] makes the comparison somewhat suspect. The correlation in figure 2c is not very good, e.g. around 1200 AD. This looks like the usual wiggle-matching, but the paper is, of course, a valuable addition to the debate.

The smoothed blue d18O curve in Figure 2B does not match the same curves in 2c and 2d for the past 100 years. There is also some slight confusion as to the labeling of the panels in Figure 2. [e.g. “The 10Be series (Figure 2a)???”].
A perennial problem with these comparisons is that the are several proxies to choose from and the choice has a great impact on the conclusions. Weber and Higbie has some cautionary words on that: http://arxiv.org/abs/1003.4989
“galactic cosmic ray intensity changes which affect the production of 10Be in the Earths atmosphere are not the sole source of the 10Be concentration changes and confirm the importance of other effects, for example local and regional climatic effects, which could be of the same magnitude as the 10Be production changes”
and http://arxiv.org/abs/1004.2675
“We have compared the yearly production rates of 10Be by cosmic rays in the Earths polar atmosphere over the last 50-70 years with 10Be measurements from two separate ice cores in Greenland. These ice cores provide measurements of the annual 10Be concentration and 10Be flux levels during this time. The scatter in the ice core yearly data vs. the production data is larger than the average solar 11 year production variations that are being measured. The cross correlation coefficients between the yearly 10Be production and the ice core 10Be measurements for this time period are <0.4 in all comparisons between ice core data and 10Be production, including 10Be concentrations, 10Be fluxes and in comparing the two separate ice core measurements. In fact, the cross correlation between the two ice core measurements, which should be measuring the same source, is the lowest of all, only ~0.2. These values for the correlation coefficient are all indicative of a "poor" correlation. The regression line slopes for the best fit lines between the 10Be production and the 10Be measurements used in the cross correlation analysis are all in the range 0.4-0.6. This is a particular problem for historical projections of solar activity based on ice core measurements which assume a 1:1 correspondence. We have made other tests of the correspondence between the 10Be predictions and the ice core measurements which lead to the same conclusion, namely that other influences on the ice core measurements, as large as or larger than the production changes themselves, are occurring. These influences could be climatic or instrumentally based…"

So, perhaps there is correlation of climate with climate to some extent.

ya Lief, they wiggle matched. That’s a problem.
Also, folks note that they are talking about a LOCAL effect. and further the solar component only explains a fraction of the response, albeit substantial. The fact that they find a dynamical response in N latitude SST, doesn’t motivate a similar conclusion for the ROW.

“We report on a 1000 year long oxygen isotope record in sediments of the eastern Norwegian Sea which, we argue, represents the temperature and transport of warm Atlantic waters entering the Nordic Sea basin via the North Atlantic Drift and the large-scale Meridional Overturning Circulation. The single-sample resolution of the record is 2.5–10 years and age control is provided by 210Pb and 137Cs dating, identification of historic tephra, and a 14C “wiggle-match” dating method in which the surface reservoir 14C age in the past is constrained rather than assumed, thereby eliminating a large source of chronological uncertainty. The oxygen isotope results indicate decade- to century-scale temperature variations of 1–2°C in the shallow (∼50 m deep) subsurface which we find to be strongly correlated with various proxies of past solar activity. The correlations are synchronous to within the timescale uncertainties of the ocean and solar proxy records, which vary among the records and in time with a range of about 5–30 years. The observed ocean temperature response is larger than expected based on simple thermodynamic considerations, indicating that there is dynamical response of the high-latitude ocean to the Sun. Correlations of our results with a gridded temperature reconstruction for Europe are greater in central Europe than in coastal regions, suggesting that the temperature and transport of warm Atlantic waters entering the Nordic Basin and the pattern of temperature variability over Europe are both the proximate responses to a change in the atmospheric circulation, consistent with a forced shift in the primary modes of high-latitude atmospheric variability”

I still doubt palaeontological reconstructions which are always carried out in certain restricted areas and have huge question marks hanging over them – validity – representativeness – statistics – intrepretation and as they say, much, much more.

I believe that the most accurate records are contained in old history books and many historical records, that show that it was relatively warm in the Roman and Medieval warm periods and also quite recently; while relatively colder in between. I’m working on calculating error bars to clarify that last statement. I’ll be back shortly on that.

Anybody thinking that the current epoc is the hottest evah, can be ignored until I’m back to report with my very precise calculations.

The Earth’s magnetic field in the wider Arctic area has changed approximately in inverse proportionality with the solar activity,http://www.vukcevic.talktalk.net/LFC9.htm
which is somewhat different to change in the Earth’s magnetic dipole (magnetic poles rates of change are different). This would suggest that any study based on the CR’s generated isotopes in the Arctic area, if referenced to the magnetic dipole rather than local field, may unintentionally show degree of ‘solar activity bias’.

Wiggle-matching the proxy to fit the solar record would be poor practice, but that is not what they are doing here. The wiggle matching they refer to is to wiggle-match the radiocarbon dates to the radiocarbon calibration curve. This procedure makes use of the wiggles in the calibration curve to get a more precise age estimate. It is a valid procedure. I would have preferred to calibrated the dates and constructed the age-depth model constructed using a Bayesian deposition model (for example in OXCAL), but the results would probably be little different.

“consistent with a forced shift in the primary modes of high-latitude atmospheric variability”

Time to look at that atmospheric chemistry proposition of mine a bit more closely.

Then consider the response of the ocean cycles to cloud cover and albedo changes:

” indicating that there is dynamical response of the high-latitude ocean to the Sun”

Then what I’d like to know is whether the changes in cloud quantities and global albedo (apparently linked to solar changes) can be put down to Svensmark’s cosmic ray effect, Lindzen’s Iris effect or my jetstream positioning/meridionality effect.

I think changes in global radiative balance merely follow the energy budget effects of chemical processes within the atmospheric portion of the climate system but that those chemical processes are linked to the changes in the mix of wavelengths and particles from the sun which then influence surface pressure distribution, cloudiness, albedo and the amount of energy entering the oceans.

The oceans then have their own internal circulations that ration the return of that energy to the air over several overlapping timescales of up to at least 1000 years (the length of the thermohaline circulation).

vukcevic says:
March 24, 2011 at 1:41 amany study based on the CR’s generated isotopes in the Arctic area, if referenced to the magnetic dipole rather than local field, may unintentionally show degree of ‘solar activity bias’.
The CRs do hardly see the local Arctic field, but are governed by the dipole. Any, now matter how complicated, magnetic field at a great distance will be dipolar, as the field strength of a multipole of degree n falls off with distance, a, as (1/a)^(n+1). So at 10 Earth radii, the dipolar field (n=2) is down to 1/1000, but the quadrupolar field (n=3) is down to 1/10,000, and the next higher one (n=4) is down to 1/100,000, etc.

John Marshall says:
March 24, 2011 at 5:56 am
if we removed all CO2 from the atmosphere life would be so much better.
———————-
Only a fool would believe that. And only a scoundrel would seek to foist this strawman onto others.

I challenge you to either retract or give a quote from any scientist who would subscribe your stupid argument.

REPLY: Apparently Mr. Telford’s sarcasm detector is broken, which is why it is always important to use the /sarc tag at the end to help the humor challenged – Anthony

steven mosher says:
March 23, 2011 at 11:29 pm“…Also, folks note that they are talking about a LOCAL effect. and further the solar component only explains a fraction of the response, albeit substantial. The fact that they find a dynamical response in N latitude SST, doesn’t motivate a similar conclusion for the ROW…”

However, it is probable that changes in weather regime in the NH subarctic zone is a key precursor for global climate change.

“I would have preferred to calibrated the dates and constructed the age-depth model constructed using a Bayesian deposition model (for example in OXCAL), but the results would probably be little different.”

I wasnt able to look at the full paper, But recalled an interesting presentation at AGU WRT wiggle matching and carbon dating.. err memory is failing me now but it was showing a preference for a baysian approach over the wiggle matching.

“So, perhaps there is correlation of climate with climate to some extent.”

That’s funny or should that be disheartening!

Leif do you know roughly the centennial scale variation in TSI from the Hoyt and Schatten reconstruction, I can’t access the full paper? Also why is it still so popular? Alot of publication even now are using it to compare with climate reconstructions. There seem to be many newer TSI reconstructions (persumably with much lower TSI variation assuming you’re going to tell me the variation is high in H&S). Is it used because it basically ‘works’ when it comes to telling a neat story? I imagine a just right solar influence helps with the present AGW theory, too high or too low and you have to start think hard about things?

HR says:
March 24, 2011 at 8:59 pmI can’t access the full paper?
Here it is: http://www.leif.org/EOS/93JA01944.pdf
The actual values can be found here:http://www.leif.org/research/TSI%20(Reconstructions).txtAlso why is it still so popular? Is it used because it basically ‘works’ when it comes to telling a neat story? I imagine a just right solar influence helps with the present AGW theory, too high or too low and you have to start think hard about things?
You nailed it.

Is it used because it basically ‘works’ when it comes to telling a neat story? I imagine a just right solar influence helps with the present AGW theory, too high or too low and you have to start think hard about things?

Yes. Contrary to popular belief, the “warmers do recognise solar activity as a cause of climate change. The above paper references papers by Amman, Shindell, Mann, Schmidt and others. The Shindell (with Mann & Schmidt) looked at “Solar forcing of regional climate change during the maunder minimum”. However with most solar reconstructions there is a divergence between solar activity and temperature in recent decades which to them can only mean one thing …….

The norwegian sea study seems to come to much the same conclusion as the Shindell et al study (and others), i.e. solar activity has an impact on regional temperatures – possibly due to shifts in weather patterns – but has less influence on global temepratures.

I think the answer is that regional changes via changes in the air pressure distribution are rapid as we recently saw with the extreme solar minimum.

However for the effect on albedo to alter ocean heat content significantly takes decades with the subsequent oceanic modulation of atmospheric temperatures often being out of phase with short term solar variability.

However on multicentennial timescales such as MWP to LIA to date the shorter term. regional and apparently chaotic behaviour of the climate is largely smoothed out and we see solar activity/ ocean heat content/ air circulation behaviour and atmospheric temperatures all trending in the same direction on average over time.

So during the MWP as a whole, as opposed to shorter time spans, the sun was active, ocean heat content rose, the jets moved poleward and atmospheric temperatures rose together , just as happened in the late 20th century.

And of course in the descent from MWP to LIA the direction of trend in all those parameters was reversed.

The critical point is that one must look past the shorter term timescales when the competing influences are as often as not offsetting one another temporarily and regionally to obscure the multicentennial global background signal.

Stephen Wilde says:
March 25, 2011 at 6:00 amSo during the MWP as a whole, as opposed to shorter time spans, the sun was active, ocean heat content rose, the jets moved poleward and atmospheric temperatures rose together , just as happened in the late 20th century.
The late 18th century and middle 19th century were as active as the late 20th….

“The late 18th century and middle 19th century were as active as the late 20th….”

Maybe so but you have ignored this:

“The critical point is that one must look past the shorter term timescales when the competing influences are as often as not offsetting one another temporarily and regionally to obscure the multicentennial global background signal.”

Taking words out of context is not helpful.

We just saw what happens when the air circulation systems respond to a very low level of solar activity.

You suggested that because the level of solar activity was at a level commensurate with the Maunder Minimum then we should instantaneously enter Maunder Minimum climate conditions.

Well in terms of the surface pressure distribution we probably did for a while.

However (so far) it has not lasted long so we are as yet nowhere near Maunder Minimum conditions globally.

However what do you think would happen if the recent scenario went on for 50 to 100 years?

In my opinion we would be duplicating the Maunder Minimum.

Your earlier comments about radiative processes and the inability for the system to ‘store’ energy do not apply here. What matters is chemical processes in the atmosphere feeding or not feeding a vast oceanic energy storage system.